Method of fixing finger-prints.



shellac or its equivalent a'dhe'sive or coating;

-' STAT EDWIN HEDRICK, 0F KENILWOBTH, ILLINOIS.

, METHOD OIF FIXING: FINGER-PRINTS.

3T0 Drawing.

To all whom it may concern:

Be it known that I, EDWrN Hnnmon, a citizen of the United States, residing at village of Kenilworth, in the county of Cook .and State of Illinois, have inventedcertain "after which the oily and practically invisible lines are, so to speak, developed by dust ng over them a material containing a pigment so that the lines become clearly visible. To preserve these lines and to prevent smearing or obliteration, the imprint-is sprayed with a fixing material, such as a solution of shellac in alcohol. 1

By the present method, Tmmix-with the developing powder a latent binding or fix:

ing agent in the form of finely powderedshellac, gum, or other suitable adhesive, and

then spray onto the developed pr'iiit a suit,-

able solvent, such as grain or. Wood alcohol,-

by, which means the finely owdered Qadh; sive material is dissolved an there is formed over the print a transparent covering:

' The developing powder which has heretofore been used consisted of lamp blacker other pigment and a body substance, such as wheat flour. I may addthe powderedshellac, gum, or other material to this'pow der, or'may substitute or. .the whole or a portion of the body material, the powdered material. g v l A The method ofoperation is aSjOlZlfOWsf-g a i The fingers, if rnot suificiently oily, tfilgf/ pressed-upon spela-lly. prepared oil tcai-daqoi ii which consists in pressing the oily '.:as a 1coho1-.=

Specification of-Letters Patent. t t a 19, 191&

Application filed June 4,1917. Serial No. 172,784.

rubbed upon the hair, and the oily fingers are thenv pressed upon paper or other suitable surface. The practically invisible prints are then dusted with the developing powder comprising the pigment and the powdered shellac, with or without additional powsolution of the adhesive in the solvent. Y

While I havedescribed my invention in detaiLit is to be understood that it is not limited to theparticular materials specified,

except as indicated in the claims.

I cl m. l. .TThe process of making finger prints which consists in pressing the oily fingers on an impression surface, dusting the impression with a powder containing a pigment and an adhesive, and then spraying onto. said impression a solvent for said adh s' ve.e

2.. The process of making finger rints on an impression surface, dusting the impression with a powder containin a pigment and-shellac, and then spraying onto "In test mony whereof Iiaflir: my signature 1 i ",in'pre'senoe ofgrtwo witnesses.

- nDWIN HEDRICK,

.WAILTER F; LYNCH, Ivan Srarnnns.

ngers saidim ression a solvent for the shellac such. 

